(1 point) Based on a random sample of 50, a 95% confidence interval for the population proportion was computed. Holding everything else constant, which of the following will reduce the length of the confidence interval by half? (CHECK ALL THAT APPLY): "A. Change the confidence level to 99.7%. '7' B. Quadruple the sample size. "' 0. Double the sample size. '7' D. Change the confidence level to 68%. "' E. Decrease the sample proportion by half